An Engineer’s Radio Flyer - Hot Rod Anything!

When Tad Berkebile walks into a hardware store, he daydreams about parts and pieces that were never intended to work together. Tad, a retired engineer, has been inspired to create various projects in his garage after walking the aisles of Harbor Freight and Northern Tool. His latest is a take on the classic Radio Flyer. He calls his the “Zephyr Flyer.” “You see a lot of little red wagons around swap meets. A lot of guys have pretty neat ideas, but no one has done this,” says Tad. He started his build with a 5.4hp Evinrude Zephyr two-stroke flat-four outboard boat engine. He mounted the 160cc engine horizontally between the framerails of his homemade wagon and built an intake manifold to mount a new diaphragm carburetor vertically. He machined the lower half of a vintage Johnson Seahorse outboard-motor outdrive to act as a small transmission.

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1] That's a cut-down mower seat purchased new from a hardware store.2] There's a ball shifter in the middle that operates Forward, Neutral, and Reverse gear inside the bottom section of the outdrive. 3] The air cleaner is a Speedway Motors valve-cover breather.4] The gas tank and water tank are backpacker-stove fuel tanks. The water system is not pressurized, so it overflows into a catch can when hot.5] The nose was built from a vintage South Wind Heater, which was an interior heater from early '30s cars. Tad made cutouts for grilles and hand-fabbed the hood.6] The wagon body was stretched 6 inches and widened 3 inches. The steering comes from two Radio Flyer handles that connect to the wheels with a tie rod.7] It's hard to see, but to keep the driver's thighs off the exposed engine in the middle, there are two brushed aluminum pieces that came from the engine's original shroud.8] The front suspension uses a dropped axle mounted by way of two upside-down quarter-elliptic leaf springs.

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1] The engine is a 160cc Evinrude Zephyr water-cooled flat-four outboard boat engine.2] The radiator is a heater core from a 1965 Mustang. 3] The kart is filled with trick pieces like a chain-driven water pump from Northern Tool and Equipment. (Hidden underneath the engine.)4] Tad machined down a rear go-kart brake to fit into a Pedicab differential found at a hardware store. The rear axles have CV joints and look like halfshafts.

In lieu of a prop, Tad fitted a sprocket and centrifugal clutch from a go-kart to the outdrive, which feeds a chain that spins a transfer case and then another chain to a differential. Tad is experienced with go-kart engines, and he says he “put a lot of outboard engines on go-karts when I was young.”

An elliptical spring mounted to the top of the rear carriage and both rear hubs gives the rear suspension its bounce. In between the homemade upper and lower front control arms are shortened Polaris Sportsman 700 all-wheel-drive ATV axles and hubs that had to be turned and re-drilled to fit the go-kart wheels Tad snagged off eBay.

Tad made many of the parts for his Zephyr at the night machining class offered by Placer Adult School in Auburn, California. “I got a lot of ideas and help from the other guys,” Tad says. It took him three years to complete, but that’s devoting roughly seven hours a week to the project—it’s a hobby, not a job. With 800 hours invested, Tad says, “I’d have charged $80,000 just for the fabrication, but I did it for the fun of it. It’s my son Bret’s wagon.” He doesn’t want that much for this one, though; if someone wants it, Tad will part with it for $3,900.